Improved machine for turning spiral forms



' J40. HINTZ. MACHINE FOR TURNINQ SPIRAL FORMS.

PATENTED NOV. 10, 1857.

Y We may arm r We fiz/wr UNITED STATES JOHN C. HINTZ, OF CINCINNATI,OHIO.

IMPROVED MACHINE FOR TURNING SPIRAL FORMS.

Specification forming part of Letters Patent No. [8,588, dated November10, 1857.

To all whom it may concern:

Be it known that 1, JOHN G. HINTZ, of Oincinnati, Hamilton county, Ohio,have invented a new and useful Machine for Turning Spiral Forms; and Ido hereby declare the following to be a full, clear, and exactdescription thereof, reference being had to the annexed drawings, makingpart of this specifictaion.

My invention has for its object a means of producing spiral or otheroblique carving on wood without roughing or turning the grain, and isprincipally designed .for the forming of spiral flutings and moldingsupon posts and other parts of household furniture.

1n the accompanying drawings, Figure 1 is a perspective view of theapparatus with the cutting-bits and their accessories elevated. Fig. 2is a perspective view of aportion of the machine, exhibiting detailsherein after explained.

A rectangular frame, L, is supported in a horizontal position on thetops of four posts, A A A A, two of which,A A, for convenience ofreference, are called the front posts, and the other two, A A, the rearposts. One end of the frame L is hinged, l, to tops of the frontposts,AA. The other end of theframeL simply rests upon a transom, A,which unites the tops of the posts A A. Journaled athwart the frame L,near its free end, is the driving-shaft B, mounted with suitablepulleys, 0 D D. Depending vertically from this shaft Bis a secondrectangular frame, L, whose lower end is susceptible of a compoundmotion derived from the elevation or depression of the frame L at itsfree end and its own capacity of vibration on the shaft B. These twoframes collectively I style the swinging and gravitating frame, L L.

O is a brace, (removable at will,) which, bein g at one end hinged toone of the rear posts, A, and at the other end to the swinging frame L,restricts the latter to an up-anddown motion.

19 is a bracket, which projects forward from the other rear post, A.This bracket, in the present illustration, has its upper edgehorizontal, but a concave or other form is employed in some cases. Thisbracketis adjustable vertically on the post, and when used is elevateduntil its upper edge presses a small roller, q, projecting from theframe L, thus supporting the said frame with its suit of cutting-bitsand their accessories for purposes hereinafter explained. A horizontalrail, L, unites the lower extremities of the frame L and bears on itsfront a number of bearings, Z, which hold the journals ofa rotatingcutter of the following construction k k are two shafts supported by thebearings l aforesaid accurately in line with each other To the inner oradjacent ends of these shafts are fixed two similar stocks or heads, KK, (each attached to and revolving with its respective shaft.) To eachhead K K is attached a set of bits, 7c 70, one set having itscutting-edges adapted to form the right half of the desired flute ormolding, and the other the left half thereof, the two sets being pointedin opposite directions of rotation and having their adjacent edgescoincident, or nearly so, with a common plane of rotation. The two headsthus equipped are so belted, E. E, from the driving-shaft as when inmotion to revolve in opposite directions, so that one set cuts forwardin the forming furrow or molding, and the other set cuts backward,immediately opposite to it, at the same time, both thereby cuttingtoward the grain of the wood and leaving a smooth surface. The two setsor halves thus combined, so as in their collective capacity to cutsmoothly an entire groove or molding oblique with the grain of the wood,I style the duplex cutter.

The arrangement of cutters in the present illustration is such as isadapted for forming a right spiral. For a left spiral the pointing anddirection of the bits and the belting of the shafts 7t 75 are allreversed. The entire swinging frame L, with its duplex cutter andaccessories, is capable of being elevated or depressed bodily by meansof rack and pinion m n.

a a is a customary lathe-bed, which at or about its mid-length ispivoted, u, to the floor, at a point perpendicularly beneath the centerof the cutter-head k is, so as to permit the adjustment of the bed in ahorizontal plane to any desired angle to the right or left ofparallelism with the shaft of the cutter-head.

o is a scale mapped on the floor to enable the accurate adjustment ofthe bed.

11 c d e f g h i j r r constitute, respectively, the carriage, head andtail stocks, gearing, and spindles of a customary screw cuttinglathe,being such as to cause any given point on the stuff to describe a spiralpath winding to the right or left according to whether the rack i or jis brought into service, the pitch of the spiral depending on therelative sizes of gearing employed.

w is a rest, adjustable in height by means of wedge movement to or othermeans, and provided with jaws a: or, adjustable toward and from eachother, so as to embrace or grasp the stick to be operated on, the wholewhen adjusted being secured in position by a bolt, 10'.

y is a gage or mouthpiece attached (with vertical adjustability) to therail L of the frame L, and which, resting on the surface of the stuff,serves to control the depth of cut of the bits, and to insure a uniformshaving throughout the length of a taper-stick or of one having anyother varying longitudinal contour, the frame L rising and falling withthe surface of the stuff. The swinging and gravitatin g frame and itsappendages are so counterbalanced by weight and pulley F, or otherwise,as to lighten the pressure of the gage y to about forty or fifty pounds.For paring off the slight comb or seam left by the rotary bits, I employa pair of crank-wheels, s s, which, by means of pitman t, impart, whendesired, a more rapid motion to the carriage, the gearing e f g, &c.,communicating a rotary motion to the spindle r of corresponding relativespeed. The bits employed in connection with this motion are a pair offinelysharpened blades, 2 2', which may be automatically fed to the workby the following plan of construction: The bifurcated bit-stockZ has aprismatic stem, 1, screw-threaded, 1, at its lower end, so as to work inthe screw-threaded eye of a ratchet-wheel, 2, and thereby to slightlydepress the rest Z at every motion of the carriage, this intermittentmotion of the ratchet being imparted by the spring-pawls 4 4 impingingagainst tappets 3 (one shown) on the carriage.

The operation is as follows: Suppose, for example, it is desired toproduce a spiral fluting on a taper bed-post. A piece of timber that hasbeen turned to the desired taper form in the usual way is centered orfixed between the spindles r r and the rest to w-w m 00, so adapted toit as to afford it support underneath and on each side without impedingits rotation. The gage y is then so adjusted as to allow the bits 70 7ato cut into the timber to a suitable depth. A pinion, h, having beenattached, of suitable size to impart the desired pitch of spiral, andthe carriage I) adjusted to an equivalent angle with the plane ofrotation of the bits, the latter are now set in motion and the frame L Llowered by means of the rack and pinion m at until the gage y rests onthe stuff. The gearing e f, 850., being then set in motion, impartssimultaneously a rotary motion to the spindle r and a longitudinalmotion to the carriage b,-resulting in the cutti lg a spiral groovearound the post. The gagey resting on the stuff causes the cutting bitsaccurately to follow its taper, and if it be desired to leave a portionof the post without spiral, for carving or other purpose, this isaccomplished by raising the frame L L by means of the rack and pinion mn and lowering it again at the right moment. The bed a a being soadjusted that the bits rotate in a plane precisely coincident with thedirection of the groove at the pointwhere they cut it, and the bitsrotating in opposite directions, as indicated by red arrows, a veryaccurate and highly-finished fiuting is accomplished, requiring littlesubsequent manipulation. When it is desired to produce a "left spiral,the heads K K are belted to run in the opposite direction to those whichthey followed before and a left set of bits inserted, thosedescribed-being convertible by being basiled on the reverse side of theblade. 1f, then, the same pitch of spiral is desired, it is simplynecessary to shift the rack 2' out of gear and the rack j in gear, andto shift the lathe over an equal distance on the other side of zero onthe scale V. The several motionsthen proceed as before. By cuttingspiral grooves in both directions rhomboidal figures are produced ofbeautiful effect. The spiral groove being cut, the frame L L iselevated, the pitman t attached, and the bits 2 a suitably adjusted toshave off the seam left by the bits K k K k. The rotary cutter may beadapted to cut a spiral or oblique groove on a prismatic post asfollows: The brace 0 is detached and the frame L L lowered until theroller q rests on the bracket 1), the latter having been previously soadjusted as to impart the desired depth of cut. The bits k 70 being thenrotated and at the same time moved to and fro in the horizontal path towhich they are confined or guided by the bracket 1), the spindle r isheld stationary by any customary device. A fluting on one side'beingthus made, the pinion h is brought into gearand the stuff issimultaneously advanced and rotated until the next side or facet isuppermost, when a second tluting, in continuation of the last, is madeby the means already described, and so on until completion. A flat facetof any desired length may be produced by sliding the carriage to and frowhile the bit is operated as last described.

This machine may be advantageously employed in forming a superiorquality of bench and other large wooden screws.

I do not claim the oppositely-rotating cutters as new in themselves; but

I claim as new and of my invention herein- 1. In combination with theadjustable screw cutting-lathe the described construction andarrangement of the gravitating frame L, and concentrically andoppositely rotating cutters K K, whereby the latter are made to cut inunison and always over a point in the axis of the piece, in the mannerand for the purposes set forth.

2. The pair of finishing-bits z z, operated automatically by means ofthe screw-stem 1,

ratchet-wheel 2, tappets 3, and spring-pawls 4, as described.

3. In combination with the adjustable screw cutting-lathe, rotarycutters, and gravitating frame, as aforesaid, the describedconstruction. and arrangement of the roller q and bracket 19, whereby(the brace 0 being disconnected) the said cutters may be vibrated in a(substantially) horizontal plane at any desired angle to the stufl forthe production of spiral or oblique flutings on prismatic posts, asexplained.

In testimony of which invention I hereunto set my hand.

JOHN C. HINTZ. Attest:

GEO. H. KNIGHT, J AS. H. GRIDLEY.

